You may have to do some trial and error here but rates are usually reasonable and you can read reviews and profiles of potential workers. (edwardsbrothersmalloy.com)
In theory, it addresses critical shortages by putting employers directly in touch with potential workers abroad. (canadianlawyermag.com)
They know there are millions, may be even billions, of other potential workers around the world who will happily take your place. (newscientist.com)